1 /* 2 * module.c - module sysfs fun for drivers 3 * 4 * This file is released under the GPLv2 5 * 6 */ 7 #include <linux/device.h> 8 #include <linux/module.h> 9 #include <linux/errno.h> 10 #include <linux/slab.h> 11 #include <linux/string.h> 12 #include "base.h" 13 14 static char *make_driver_name(struct device_driver *drv) 15 { 16 char *driver_name; 17 18 driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name); 19 if (!driver_name) 20 return NULL; 21 22 return driver_name; 23 } 24 25 static void module_create_drivers_dir(struct module_kobject *mk) 26 { 27 if (!mk || mk->drivers_dir) 28 return; 29 30 mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj); 31 } 32 33 void module_add_driver(struct module *mod, struct device_driver *drv) 34 { 35 char *driver_name; 36 int no_warn; 37 struct module_kobject *mk = NULL; 38 39 if (!drv) 40 return; 41 42 if (mod) 43 mk = &mod->mkobj; 44 else if (drv->mod_name) { 45 struct kobject *mkobj; 46 47 /* Lookup built-in module entry in /sys/modules */ 48 mkobj = kset_find_obj(module_kset, drv->mod_name); 49 if (mkobj) { 50 mk = container_of(mkobj, struct module_kobject, kobj); 51 /* remember our module structure */ 52 drv->p->mkobj = mk; 53 /* kset_find_obj took a reference */ 54 kobject_put(mkobj); 55 } 56 } 57 58 if (!mk) 59 return; 60 61 /* Don't check return codes; these calls are idempotent */ 62 no_warn = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module"); 63 driver_name = make_driver_name(drv); 64 if (driver_name) { 65 module_create_drivers_dir(mk); 66 no_warn = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, 67 driver_name); 68 kfree(driver_name); 69 } 70 } 71 72 void module_remove_driver(struct device_driver *drv) 73 { 74 struct module_kobject *mk = NULL; 75 char *driver_name; 76 77 if (!drv) 78 return; 79 80 sysfs_remove_link(&drv->p->kobj, "module"); 81 82 if (drv->owner) 83 mk = &drv->owner->mkobj; 84 else if (drv->p->mkobj) 85 mk = drv->p->mkobj; 86 if (mk && mk->drivers_dir) { 87 driver_name = make_driver_name(drv); 88 if (driver_name) { 89 sysfs_remove_link(mk->drivers_dir, driver_name); 90 kfree(driver_name); 91 } 92 } 93 } 94